A Maricopa County Superior Court judge declared a mistrial Monday when a jury couldn't reach a unanimous life or death verdict against a man who killed two teens during a 2011 drug deal in Mesa.

Jesus Busso-Estopellan, 28, who had prior drug convictions, is believed to have lured Olek Wladyszewski, 19, to Mesa on June 29, 2011, ostensibly to sell him pills. Wladyszewski brought his friend, Tyler Webster, 18, to the meeting, and Busso-Estopellan shot and killed both of them in Webster's car. Webster was able to call 911 before he died.

A mugshot of Jesus Busso-Estopellan(Photo: Maricopa County Sheriff's Office)

Busso-Estopellan was found guilty of two counts of first-degree murder and one count of misconduct with weapons in February, and the jury found aggravating factors to qualify him for a death penalty stage. Those aggravated factors included that multiple murders had been committed and that in Webster's case, the murder was especially cruel, heinous or depraved. Prosecutor Juan Martinez maintained that Busso-Estopellan had wounded Webster and then returned to finish him off.

The trial's mitigation phase, when the jury considers factors that may convince them to impose a life sentence instead of a death sentence, lasted until April 9. The jury deliberated until April 30 and said it had reached an impasse.

Judge Erin Otis declared a mistrial.

Busso-Estopellan's guilty verdicts stand. The Maricopa County Attorney's Office did not immediately say whether it would retry the penalty stage before a new jury to try to obtain a death sentence.

If a prosecutor cannot persuade a new jury to reach a unanimous verdict, the defendant would automatically be sentenced to life in prison.